With the explosive growth of various technologies, rare-earth elements are increasingly vital to sustain that growth. A rare-earth element (REE), as defined by IUPAC, is one of a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides, as well as scandium and yttrium. Rare-earth elements are cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu), neodymium (Nd), praseodymium (Pr), promethium (Pm), samarium (Sm), scandium (Sc), terbium (Tb), thulium (Tm), ytterbium (Yb) and yttrium (Y). Heavy rare-earth metals are defined as the high atomic number lanthanide rare-earth metals: dysprosium (Dy), erbium (Er), gadolinium (Gd), holmium (Ho), lutetium (Lu), terbium (Tb), thulium (Tm), and ytterbium (Yb).
Rare-earth elements are used to build items such as batteries, permanent magnets, and displays. Rare-earth elements can also be used in various processes such as refining crude oil. An estimated distribution of rare-earth elements by end use is as follows, in decreasing order: catalysts, 60%; metallurgical applications and alloys, 10%; ceramics and glass, 10%; glass polishing, 10%; and other, 10%.
Due to the costs of extracting REEs, and the geographic distribution of known geologic deposits being mined for the rare-earth elements, a large percentage of REEs are provided in one particular region of the world. The estimated value of rare-earth compounds and metals imported by the United States in 2015 was $150 million, a decrease from $191 million imported in 2014. Finding sources of REEs and determining methods of concentrating or extracting those REEs are highly desirable.
It is with respect to these and other considerations that the various configurations described below are presented.